The Met said Kiddie, from Ruislip, was dismissed without notice by a gross misconduct panel.

Westminster Borough Commander Chief Superintendent Paul Rickett said: “Police officers join the Met to protect and serve the public and I was extremely shocked to learn and indeed see what happened."

"Where an officer's behaviour falls short of the very high standards that we and the public expect of them, then it is only right that they are held to account and PC Kiddie has paid for his actions today.

"Behaviour such as this casts a shadow over the thousands of officers who are on duty right now demonstrating bravery, compassion, integrity and professionalism."

Kiddie was previously investigated by the police watchdog, the Independent Police Complaints Commission, for deploying tear gas during protests in Oxford Street in January 2011.